Methods form an electronic semiconductor device that includes a body having a first side and a second side opposite to one another and including a first structural region facing the second side, and a second structural region extending over the first structural region and facing the first side. A body region extends in the second structural region at the first side. A source region extends inside the body region and a lightly-doped drain region faces the first side of the body. A gate electrode is formed over the body region. A trench dielectric region extends through the second structural region in a first trench conductive region immediately adjacent to the trench dielectric region. A second trench conductive region is in electrical contact with the body region and source region. An electrical contact on the body is in electrical contact with the drain region through the first structural region.